This invention relates to a modular, spool-operated, directional valve. More particularly, it relates to the construction and assembly of the modules comprising the valve body and the mounting of the valve body on a subplate.
A valve body constructed from a plurality of identical modules may be assembled by means of bolts as shown in U.S. Pat. No. 3,915,194, which is assigned to the assignee of the instant invention. In the structure disclosed in that patent, a plurality of identical valve block modules are assembled by having alternate blocks inverted or rotated such that opposite faces are mated and a pair of bolts pass through one module and thread into an adjacent module to form a manifold assembly. This assembly is then bolted to a subplate. Valve block modules can also be assembled by tie bolts which pass through a plurality of valve modules and clamp them together. An example of the use of tie bolts is shown in U.S. Pat. No. 3,504,704.
Most modular valve body assemblies are mounted on a subplate which provides porting for fluid supplied to and received from the modular valve body. Typically, each module of the valve assembly is connected to the subplate by means of fasteners, such as bolts, which pass through the module. This means that each module must be large enough to provide space for fasteners which connect the module to the subplate as well as for the fasteners which interconnect the modules.
A disadvantage to a modular valve construction in which bolts are used to interconnect adjacent valve modules and to connect the modules to a subplate is that the fasteners take up considerable space and cause the valve structure to be enlarged. For a given size of valve this reduces the size of the ports and bores which can be used in the valve and reduces the capacity of the valve. The use of such fasteners also increases the complexity and cost of manufacturing the valve. Additionally, if one valve module has to be changed, the entire modular assembly must be disassembled.
It is desirable to provide a compact modular valve in which a plurality of individual modules can be assembled to provide a modular valve body without having fasteners pass through the bodies of adjacent modules, and in which the valve body is mounted on a subplate to form a modular valve without having fasteners pass through the bodies of the modules to attach the modules to the subplate.